On Mon, 27 May 2019 12:04:58 -0600
Chris Murphy <lists(a)colorremedies.com> wrote:
On Mon, May 27, 2019 at 11:27 AM stan <upaitag(a)zoho.com>
wrote:
>
> Yes, the firmware is UEFI. But, the hard drives have been in use
> with older hardware that wasn't. My understanding is that it is
> difficult and chancy to convert from legacy partitions to GPT
> partitioning. Is that false?
It should be possible.
# fdisk -l /dev/
ideally the first partition starts at LBA 2048. If not...well cross
that bridge later.
Next run gdisk on this device. It will read the MBR, create a GPT from
it in memory, and you can write out GPT to disk with the 'w' command.
That's it. You need free space on that drive for the installer to
create an EFI System partition, which contains bootloader stuff rather
than the MBR gap.
Per the UEFI spec, this should not be necessary, but due to past
experience with bugs, I would probably opt for zeroing the first 440
bytes of LBA 0 on this drive, which is where the stage 1 (BIOS) GRUB
bootloader is located. On UEFI all the GRUB stuff is on the EFI System
volume.
# dd if=/dev/zero of=/dev/becareful bs=1 count=440
It seems that the above won't be necessary, as I must have originally
formatted the drive as GPT, and forgotten I'd done so.
I was able to switch the firmware to strictly BIOS from UEFI/BIOS
hybrid, with UEFI preferred. That allowed the installer to proceed.
Unfortunately, it hung while trying to write an mbr, though everything
else worked; it installed software, I was able to set users and
passwords. I suspect that is because the disk I was installing to is
actually formatted with GPT, since it is larger than 2 TiB. It ran for
over 20 minutes at almost 100% CPU and didn't complete. So, I killed
it. But it had somehow altered something so that when I tried to boot
to the other Fedora installed on that disk, it immediately dropped to a
grub prompt. It was trying to validate partitions with os-prober at the
time I killed it, according to the log, and had hung on the existing
Fedora root partition. When I booted in rescue and looked at the disk
with fdisk, it declared that all the other partitions on the disk
except the ones I had tried to install to were Microsoft data format.
That gave me a scare, until I noticed that there was no logical
partition. Fortunately I had an older Fedora on another disk that is
actually BIOS, and when I booted that from the firmware, I was able to
boot and run it. I then ran a mkconfig there, and the os-prober found
the original Fedora on the other disk, and created boot stanzas for
it. So I was able to get back to my Fedora, the version I am writing
this from, in a roundabout way.
The issue seems to be that hybrid installs are not allowed. If I
install as BIOS, then I have to use BIOS partitioning, not gpt. And, if
I install as UEFI, for some reason it doesn't accept the existing ext4
partitions on the gpt formatted drive. Is must be possible to boot a
GPT drive from a BIOS mbr because it appears that I was doing that.
Or, did the hybrid UEFI/BIOS firmware setting allow both?
Here's the partition table for the disk from gdisk -l.
Number Start (sector) End (sector) Size Code Name
1 2097152 4194303 1024.0 MiB 8300
2 4194304 6291455 1024.0 MiB 0700
3 6291456 48234495 20.0 GiB 8200
4 48234496 572522495 250.0 GiB 8300
5 572522496 1096810495 250.0 GiB 0700
6 1096810496 5860532223 2.2 TiB 0700
7 2048 6143 2.0 MiB EF02
The first two partitions are boot, then swap, then two root partitions,
then data. The code for the partitions I was trying to install from
the iso to are now 8300, the existing Fedora is 0700.
Can I actually somehow do a UEFI install to this disk, preserving the
existing Fedora and being able to boot to it directly?
> I thought that I had done a direct install for Fedora 21. It
was
> the last time that the BFO option worked for direct install from
> the net instead of using media.
This?
https://boot.fedoraproject.org/download
That's definitely BIOS only. In theory it could be dual UEFI and BIOS,
but no one's done that work and testing. The image would be much
bigger. The ones on that page are ~1MiB. I casually estimate a dual
UEFI + BIOS image would be ~10MiB.
Yes, that's the one. The lkrn file that downloads the rest of the
boot from the net is ~300kB, but that doesn't actually boot the
computer, only downloads the next stage. Just a bootstrap. The actual
boot first stage is approximately 30 MiB, if my memory is accurate
after all this time. I remember it printing several lines of markers to
show its progress. That then downloads anaconda for the actual install,
and it proceeds just like a netinstall from that point.